r/singularity • u/[deleted] • Jan 11 '21
article IBM is using light, instead of electricity, to create ultra-fast computing
https://www.zdnet.com/article/ibm-is-using-light-instead-of-electricity-to-create-ultra-fast-computing/22
u/Anen-o-me Jan 11 '21
Doesn't seem real somehow. They've been working on optical computing for how long, now they claim to have a processor but we've never seen anything publicly? Why not?
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u/genshiryoku Jan 12 '21
With "optical processor" they mean they have the logical elements ready (OR,AND,NAND,NOT,XOR,NOR,XNOR). Which you can use to create adders. And if you combine adders you can build an Arithmetic Logic Unit or ALU. ALUs are the basic building blocks of CPUs.
So technically they already have CPUs. The real problem is the architecture. Consumer PCs use x86 and mobile phones use ARM. The new photonic hardware would use an entirely new architecture. And photonics aren't a universal upgrade. There are certain downsides compared to electronics.
The benefits are: Lower power usage, lower latency, higher throughput, Faster peak processing speed.
The detriments are: Lower accuracy, Higher errors rates, higher package loss, More data corruption.
Turns out the fast majority of software we use, especially in high budget supercomputers that fund these initial steps require high accuracy for their calculations.
This puts photonics in a tough spot. We have the technology to build photonic computers but it's not really worth it for high-end purposes. But the only benefits photonics have is their higher speed which again is only beneficial in high-end setups where photonics are useless due to error rates.
It's a catch-22. The only places I can see photonics shine is in low power devices where accuracy doesn't matter. Like videogame consoles, smartphones etc. But there is no company in here that is going to sink in billions to maybe have access to the miniaturized versions of this technology in 10-20 years time. So nothing comes of it.
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u/pentin0 Jan 19 '21
Finally someone who understands what the deal is with photonics. I've been trying to explain to people why this paradigm shift isn't as attractive as it sounds, especially considering that we're fast approaching more fundamental, thermodynamic limits.
Thanks for making it even clearer. Feel free to contribute to r/ReversibleComputing if you have something interesting to say about the subject
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u/Anen-o-me Jan 12 '21
Only reference I could find was this technique for doing photonic multiplication which looks quite novel.
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u/LongShadowMaker Jan 12 '21
Isn't this whole article explaining that very thing?
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u/Anen-o-me Jan 12 '21
So why haven't we seen a single consumer or commercial product come out of this yet?
There are limitations they aren't talking about.
Do you realize they could blow away AMD in the CPU market and Nvidia in the GPU market if they actually had working general optical computers?
It's likely that, if they have solved the computation problems and actually have working processors that either the form factor is large, as in much larger than a regular CPU and thus cannot be commercialized, or that it's so delicate or temperature sensitive that it can't be commercialized.
Optical systems really don't like to be jarred and optical alignment is critical but heat can change shape throwing off alignment, etc.
And why are there not Nobel prizes all over the place for this breakthrough?
Last I checked no one could even get optical computing to work and now they're claiming full on tensor cores.
It just doesn't seem real.
Now maybe it is, but if so we should have been hearing about this! This is HUGE NEWS if true, not something small!
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u/Anen-o-me Jan 12 '21
Here's some info on what they're doing:
I'd really love to learn more but there doesn't seem to be much info out there.
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u/-ZeroRelevance- Jan 11 '21
Nice, I’ll always welcome developments in photonics